Trump refused to denounce Moscow's interference in the 2016 presidential election and publicly criticized special counsel Robert Mueller's Russia investigation while standing alongside Putin at a press conference following their one-on-one meeting.

"They said they think it's Russia," Trump said. "I have President Putin; he just said it's not Russia."

"I have great confidence in my intelligence people, but I will tell you that President Putin was extremely strong and powerful in his denial today," he added.

The summit came just three days after Mueller handed down indictments against 12 Russian intelligence officers for their alleged roles in hacking the Democratic servers during the 2016 election campaign.